///主要用来做缓存key的工具类
class MessageCacheKey {
  static String getC2cKey(String userId) {
    return "c2c_$userId";
  }

  static String getGroupKey(String groupId) {
    return "group_$groupId";
  }

  //系统消息用户id
  static const String SYSTEM_MESSAGE_USER_ID = "SYSTEM_MESSAGE_USER_ID";
}
